THERE is a new film about the events of 9/11. United 93 is the story of the fourth plane - the one on which superbly courageous passengers took on the hijackers and forced the plane to crash into a field in Pennsylvania rather than into The White House or some other such highly-populated target.

The film is already controversial as many people are saying that the atrocity is not a suitable subject for a movie - and especially so soon after the event.

The director of the film has been meticulous in finding out as much as possible about the horrific details, even going so far as to interview families of those who died on the plane.

Mary Louise White's daughter Honor Elizabeth was one of those killed. Mrs White said producer Kate Solomon made repeated trips from London to learn more about each of the passengers. "She wanted to get a feel for my daughter's personality to help with casting. She wanted to know what I thought she might have been doing on the plane that morning."

Mary Louise White shared her many memories with the director and then, as she says, "went on faith" with the production of the movie, but still worried that it would be too over-thetop. "When I went into the movie, I deliberately sat in the last row, on the aisle, because I figured I would have to get up and get out."

That didn't happen, though. "I was scared about what I was going to see, but the way the director has the story woven with all the events of the day, from the very beginning, I can't imagine it being done any better. You're anticipating something and you're not quite sure. . . we were all crying at the end."

As a last step to ensure solidarity with the film, Mrs White said the director asked the families for feedback via teleconference immediately following the screening. "We all resoundingly said 'yes'. . . all of us.

Everyone was unanimous."

Family members of CeeCee Lyles, a former Fort Pierce police officer who was a flight attendant killed in the crashed plane, travelled to New York last Monday for the film's premiere at the Tribeca Film Festival. Afterwards, one of them said: "If people think they're ready for it, they need to see it, because I think they'll come away feeling better, I really do. If I can go into it practically puking my guts out and come out feeling good, then I think anyone else can handle it too. I think it needs to be seen."

I'm not so sure - though obviously the views of the families involved must count for a great deal. But when it came to portraying atrocities the ancient Greek theatre had the right idea, or so it seems to me. They defined some terrible events as literally "obscene" - that is not to be seen at all, but to be offstage. We are what we eat physically, and we are what we eat mentally too. It is possible to be disturbed and even corrupted by visual images and explicit narratives.

Of course the very worst atrocities have been portrayed: the Crucifixion, the concentration camps, genocide in Rwanda. I just feel uncomfortable, as if something's not right, when in effect the TV announcer says: "We are now going to show you exquisite pictures of the starving millions." It will be interesting to see how United 93 is received.

Peter Mullen is Rector of St Michael's, Cornhill, in the City of London, and Chaplain to the Stock Exchange.